Ultimate weapon stats: 30 boss, 30 ignore mob, 6 total dmg

kind of a thread hijacking, but how does boss damage/total damage stack with berzerk? i'd think multiplicative, but how berzerk is worded makes me unsure.

and about aura/echo and the such, in a strictly solo situation, %attack=%damage, except for the fact that you lose 0~0.999 attack with attack%, or if you are a thief with shadow partner, due to it having a weird formula that benefits %dmg